Diazotype material



United States Patent 2s, 09 9 Claims. (Cl. 96-91) The invention relates to diazotype material of the socalled one-component type (which consists of sheet material carrying a layer of a light-sensitive diazo compound) and of the so-called two-component type (which consists of sheet material carrying a layer comprising both a lightsensitive diazo compound and an azo coupling component).

In Belgian patent specification No. 564,343 diazotype material is described which contains a diazo compound of the general Formula 1:

in which X represents an anion, R an alkyl group having at most 4 carbon atoms, R an alkyl group having at most 4 carbon atoms or an aralkyl group having at most 7 carbon atoms, and R an alkyl group having at most 4 carbon atoms.

Diazo compounds of this type are very sensitive to the light of the mercury-vapour lamps commonly employed in the diazotype process, both of high-pressure lamps and of low-pressure lamps, and both of the actinically fluorescent and of the non-fluorescent lamps.

Diazotype material sensitized with such a diazo compound is very suitable for the visual observation of the end point of the exposure in the process of copying by the light of actinically fluorescent mercury-vapour lamps.

The diazo compounds of this type having larger alkyl groups, such as n-butyl, and those having aralkyl groups, such as benzyl, often precipitate from their aqueous solutions if the customary quantity of the stabilizer naphthalene 1.3.6-trisulphonic acid (which is practically indispensable in light-sensitive diazotype layers) or one of its salts is added to them. In practice, water is preferably used as solvent for the manufacture of sensitizing liquids for diazotype materials. Hence, if normal sensitizing liquids are employed, it is not possible to use the normal quantities of this stabilizer in intimate admixture with the said diazo compounds though adequate quantities are necessary to obtain the stabilizing effect.

Sometimes the formation of precipitates can be prevented by addition of a large excess of stabilizer, but this involves other drawbacks. The solution then penetrates too far into the support of the diazotype material to which it is applied, especially if this support is paper; the diazotype material manufactured with it develops less satisfac torily, especially in the so-called semi-wet development process, in which a thin layer of developing liquid of, for example, 8 g./m. is applied on the imagewise exposed diazotype material; the copies on the diazotype material manufactured with it often show an exposed background with a yellowish colour and sometimes serious discolouration upon exposure to the light.

The formation of precipitates can sometimes also be prevented, or precipitates already formed-can be dissolved again, by dilution of the diazo solution, but diazotype material manufactured with such a diluted diazo solution yields only very weak copies.

' diazotype material manufactured with it.

The formation of precipitates can sometimes also be prevented, or precipitates already formed can be dis: solved, by considerably raising the temperature of the water or of the solution (for example to C,.),, but this measure has a deleterious effect on the keeping qualities of the sensitizing liquid and on the quality of the In practice sensitizing liquids at room temperature or at an even lower temperature are preferably used. Small increases of temperature, for example to 30 C., may be permitted.

The diazo compounds of general Formula I having small alkyl groups, for example l-diazo 4-dimethylamino 3-methoxy benzene and l-diazo 4-dimethylamino 3- ethoxybenzene, do not, under normal conditions, give a precipitate with the said stabilizer, but they yield lightcoloured azo-dyestuffs and their coupling activity is low. Consequently, in practice the compounds with larger alkyl groups or those with aralkyl groups are preferred. They yield darker azo-dyestuffs and they couple more actively, which is especially important for diazotype material intended for semi-wet development.

Many azo-dyestuifs formed by the coupling of several of the diazo compounds according to Belgian patent specification No. 564,343 with the azo components commonly used in the diazotype process, such as phloro glucinol, 2.3-dihydroxy naphthalene, 2.3-dihydroxy naphthalene 6-sulphonic acid, Z-hydroxy naphthalene 3.6-disulphonic acid and the like, change their colour when the pH decreases. The surface of diazotype copies may turn acid or more acid after the development, either locally, for example owing to spilling of acid liquids, or wholly, for example when the copies are kept in-a moist atmosphere, in consequence of which the acid from the interior of the paper can diffuse to the surface As is known, base-paper for the diazotype process often contains rather large quantities of acid, for example in the form of alum. In consequence of a resultant decrease of the pH the said azo-dyestuffs often show an undesirable change of colour.

The compound l-diazo 4-dimethylarnino 3-methoxy 6-ch-1orobenzene, just like the corresponding compound without a chloro substituent, does not give precipitates With naphthalene 1.3.6-trisrulphonic acid or its salts during the manufacture of normal aqueous sensitizing solutions. However, its coupling activity is low and the azo dyestuffs derived from it are light-coloured.

According to the present invention there is provided diazotype material which contains a diazo compound of the general Formula II: I 1

in which X is an anion, Y a fluorine or chlorine atom, and R R and R are hydrocarbon radicals chosen from alkyl groups having at most 4 carbonatoms and aralkyl groups having atmost 11 carbon atoms, and R R and R contain together at least 6 and at most 17 carbon atoms. 7 v

The diazo compounds of this type couple more actively. than the corresponding compounds without a fluoro or chloro substituent. Moreover, compared with l-dlJZiZO 4-dimethylamino 3-methoxy -chloro'oenzene, referred to above, they are more active, give darker coloured azo dyestuffs and when used in one-component diazotype material cause less trouble with bleeding of the image portions, in which the formation of azo dyestuffs takes place during the so-called semi-Wet development Wiih an aqueous developing liquid.

. surprisinglyform smaller amounts of precipitates with naphthalene1.3.6-trisulphonic acid or its salts, many of them giving no precipitate at all. a

In consequence, diazotype material according to the invention can be manufactured With a suficiently high diazo content and with anormal content of naphthalene 1.3.6-trisu1phonic acid or one of its salts, [and then has better keeping qualifies than diazotype material of which the light-sensitive layer contains a corresponding diazo compound without a fluoro or chloro substituent and does not contain the said stabilizer.

The compatibility with the said stabilizer is not the same for allcompouuds of general Formula II. According as, for example, the size of the substituents R R and R increases, the compatibility will decrease. Yet even the compounds with the largest substituents R R and R are more compatible with the said stabilizer than the corresponding diazo compounds without a fiuoro or chloro substituent. Hence, during the preparation of sensitizing liquids for diazotype material according to the invention with diazo compounds with large substituents R R and R precipitation difliculties with the said stabilizer can be avoided more easily (for example, by a small increase of the temperature) than during the preparation of sensitizing liquids with corresponding diazo compounds Without a fluoro or chloro substituent.

Accordingly as the total number of carbon atoms of thersubstituents R R and R increases, the solubility of the diazo compounds in aqueous sensitizing liquids generally decreases. Thev compounds in which R,, R and R contain together more than 17 carbon atoms and in Which no special solubilizing substituents, such as sulphonic acid groups, are present are only slightly soluble therein.

7 The azo-dyestuti images formed in diazotype material according to the invention are more resistant to decrease of'the pH than the corresponding azo-dyestiufi images in corresponding diazotype material sensitized with corresponding diazo' compounds without a fiuoro or ch-loro substituent.

The colour of the azo-dyestutfs formed by development, with ammonia vapour, of two-component diazotype material according to the invention, containing the azo-dyestufi component 7'-hyd.roxy naphtho-1',2', 4.5- imidazole, is stronger and purer than that of the amdyestuffs formed by development, with ammonia vapour, of corresponding two-component diazotype material containing a corresponding diazo compound without a fluoro or chloro substituent.

The diazotype material according to the invention, just like that made with the aforesaid diazo compounds without a fluoro or chloro substituent, is very sensitive to the light of mercury-vapour lamps and also very suitable for'the visual observation of the end point of the exposure in the process of copying by the light of actinically fluorescent mercury-vapour lamps.

Diazo compounds which can be used in diazotype material according to the invention are:

4-dimethylamino 3-isobutoxy 6-chlorobenzene diazonium chloride, zinc chloride double salt,

4-dimethylamino Z-naphthylmethoxy 6'-chlorobenzene diazonium chloride, zinc chloride double salt,

4-diethylamino 3-ethoxy 6-chlorobenzene diazonium chloride, zinc chloride double salt,

4-N-ethyl N-n-birtylamino 3-ethoxy fi-fluorobenzene diazonium chloride, stannic chloride double salt,

4-dibenzyliamino 3-methoxy -chlorobenzene diazoniumsulphate,

4-N-hydroxyethyl N-benzylamino B-methoxy G-chlorobenzene diazonium chloride, zinc chloride double salt,

4 N methyl N 3'.4' dichlorobenzylamino 3-metho-xy 6-chlorobenzene diazonium chloride, cadmium chloride double salt,

.4-N-5-chloroethyl N-benzylamino 3-methoxy G-chloro benzene diazonlum-borofiuoride, 4-N-isopr0pyl N-benzylamino 3-ethoxy -chlorobenzene diazonium chloride, zinc chloride double salt, 4-N-methyl N naphthylmethylamino 3-ethoxy 6-chlorobenzene diazonium chloride, zinc chloride double salt.

The diazo compounds in which 125R, and R contain together at least 8 carbon atoms are particularly suitable for the manufacture of one-component diazotype material. Thisone-component diazotype material can be easily and completely developed according to the semi Wet process with a developing liquid containing phloroglucinol. Thedeveloped copies do not show bleeding.

Of the last-mentioned group of diazo compounds, those in which R represents a benzyl group are very suitable for the manufacture of one-component diazotype material.

Copies on this material can also be developed satisfactorily without bleeding according to the semi-Wet process with a developing liquid containing phloroglucinol. Moreover, they show a very clear, exposed background.

The diazotype material according to the invention may of course contain mixtures of diazo compounds. Accordingly as those mixtures have a lower content of diazo compound as described above, the diazotype material manufactured with these mixtures will also possess the advantages described to a less extent.

The diazo compounds used in the diazotype material according tothe invention may be prepared in several ways. The starting material may, for example, be p-chloro-phenol. After alkylation or aralkylation of the hydroxy group the substance is nitrated, the ortho-nitro p-chlorophenol ether is collected and reduced, and the resulting amino group is aralkylated and/or alkylated. The o-dialkyl (or alkyl-aralkyl or diaralkyl) amino p-chloro-phenol' ether obtained is subsequently provided, in the para position with respect to the amino group, with a nitroso group by treatment with nitrous acid, or it is'nitrated or coupled to diazotized 2.5-dichloroaniline. The nitroso or nitro compound or the azo-dyestuff obtained is reduced to an amino compound and this amino compound is converted into a diazonium compound by treatment with nitrous acid. The diazonium compound can be collected as a double salt, for example, by precipitation with zinc chloride or sodium borofluoride.

With regard to the above-mentioned alkylation of the amino group it is remarked that R; and R may be the same or different alkyl groups and that their carbon chains may or may not be branched.

The following examples will serveto illustrate the invention.

Example 1 White base-paper of weight g./m. for the diazotype in 1000 cm. of water and'dried. I .The sensitized surface contains approximately 0.55

millimole of the diazo compound per m. The diazotype paper has good keeping qualities. V

A sheet of the diazotype material is exposed in contact with a film positive of a line-drawing in an exposure apparatus equipped with actinically fluorescent low-pressure mercury-vapour lamps, with the film positive between the light-source and the diazotype paper. Exposure is continued until in the portions corresponding to the transparent portions of the film positive all the diazo compound has bleached out. The progress of the bleaching of the yellow diazo compound can easily be observed visually, for example, from the direction of the lamp.

The latent diazotype copy thus obtained is developed by applying on its image surface a layer of approximately 8 g./m. of the following developer:

31 g. of thiourea 6.5 g. of phloroglucinol 6.5 g. of resorcinol 2 g. of isopropylnaphthalene sulphonic acid sodium salt 5 g. of sorbitol 15 g. of saccharose 53 g. of potassium tetraborate (5 aq.)

9 g. of potassium hydroxide :.i n 1000 cm. of water.

Very soon after the application of the layer of developer the developed copy shows a strong dark brown positive azo-dyestuff image on a clear white background. The lines of the image do not show bleeding.

If instead of the above-mentioned diazo compound an equimolar quantity of the corresponding compound Without a chloro substituent is used, a precipitate is formed in the sensitizing liquid. If the non-chlorinated diazo compound is used in the absence of naphthalene 1.3.6- trisulphonic acid, no precipitate is formed, but the keeping qualities of the diazotype material produced are considerably inferior to those of the material according to the example.

The diazo compound used according to this example is prepared as follows:

Z-methoxy S-chloroaniline is benzylated. The product thus formed, 2-methoxy 5-chloro N-benzyl aniline (boiling point 15mm, 175-185 C.) is methylated to Z-methoxy 5-chloro N-methyl N-benzyl aniline (boiling point 200-210; melting point 4546 C.), and subsequently nitrated to 2-methoxy 4-nitro S-chloro N-methyl N-benzyl aniline (orange-yellow crystals, melting point 114-1l5 C.). This compound is reduced and worked up into the diazo compound in the usual way.

Example 11 White base-paper of weight 80 g./m. for the diazotype process is sensitized with a solution (at 18 C.) of:

17.5 g. of 4-N-methyl N-benzylarnino 3-methoxy 6-chlorobenzene diazonium chloride, zinc chloride double salt 100 g. of tartaric acid 30 g. of boric acid 20 g. of 7-hydroxy naphtho-1',2, 4.5-imidazole HCl-salt 0.8 g. of methyl cellulose in 1000 cm. of water and dried.

The sensitized surface contains approximately 0.45 millimole of the diazo compound per m A sheet of the diazotype paper is exposed as in Example I.

The latent diazotype copy thus obtained is developed by exposing it for some tens of seconds to hot concentrated moist ammonia vapour. A strong bright red positive image on a clear white background is obtained.

If instead of the above-mentioned diazo compound an equimolar quantity of the corresponding compound without a chloro substituent is used, a copy with a less strong and a less bright brown-red image is obtained. When the last-mentioned copy is moistened with dilute phosphoric acid, which may happen in workshops working with mordant baths, the red-brown colour of the copy turns yellow. The bright red colour of the copy according to this example, however, only changes when it is moistened with a much more concentrated phosphoric acid.

Example Ill White base-paper of weight g./m. for the diazotype process is sensitized with a solution (at 18 C.) of:

23 g. of 4-N-n.propyl N-benzylamino 3-methoxy 6-ch1orobenzene diazonium chloride, zinc chloride double salt 3 g. of tartaric acid 1 g. of citric acid 35 g. of naphthalene 1.3.6-trisulphonic acid sodium salt 20 cm. of polyvinyl acetate dispersion (Vinnapas H.60)

in 1000 cm. of water and dried.

The sensitized surface contains approximately 0.5 millimole of the diazo compound per m The diazotype paper has good keeping qualities. A sheet of the diazotype paper is exposed as in Example I.

The latent diazotype copy thus obtained is developed by applying on its image surface a layer of approximately 9 g./m. of the following developer:

40 g. of thiourea 4 g. of phloroglucinol 1 g. of resorcinol 1.2 g. of Z-ethylhexyl sulphuric acid mono-ester as sodium salt (commercially available under the name of Tergitol O8) 200 g. of tert. sodium citrate (5 aq.)

2 g. of citric acid in 1000 cm. of water.

The developing liquid has a pH of about 6. The developed copy shows a strong black positive image on a clear white background which does not show any appreciable bleeding.

If instead of the above-mentioned diazo compound an equimolar quantity of the corresponding compound without a chloro substituent is used, a precipitate is formed in the sensitizing liquid. If the non-chlorinated diazo compound is used in the absence of naphthalene 1.3.6- trisulphonic acid, no precipitate is formed, but the keeping qualities of the diazotype material produced are considerably inferior to those of the material according to this example.

If the non-chlorinated diazo compound is used in the presence of an excess of naphthalene 1.3.6-trisulphonic acid, for example 60 g. instead of 35 g., again no precipitate will be formed, but the sensitizing liquid then obtained penetrates far into the paper, the diazotype paper manufactured with it develops more slowly and less completely, and copies on this diazotype paper show an ex posed background with a yellowish colour.

The diazo compound used according to this example is prepared as follows:

Z-methoxy S-chloroaniline is converted with p-toluene sulphonyl chloride into the 2-methoxy S-chloro p-tosyl anilide (melting point 143 C.). This compound is treated with n-propyl bromide and the 2-methoxy S-chloro N.n-propyl N-p.tosyl anilide thus formed is hydrolyzed to Z-methoxy S-chloro N.n-propyl aniline (boiling point 150154 C.). This compound is benzylated and the 2-methoxy S-chloro N.n-propyl N-benzyl aniline thus obtained (boiling point 186-190 C.) is converted into the desired diazo compound by nitrosation, reduction, and diazotization.

Example IV Cellulose acetate film of g./m. superficially hydrolyzed on one side, is sensitized by immersing it in a solution (at 18 C.) of:

21 g. of 4-di-n.propylamino 3-methoxy 6-chlorobenzene diazonium chloride, zinc chloride double salt 5 g. of tartaric acid 2 g. of boric acid 20 g. of naphthalene 1.3.6-trisulphonic acid sodium salt 250 cm. of ethanol in 750 cm. of watensqueezing off the excess of liquid, and drying the film.

The sensitized surface contains approximately 0.8 millimole of the diazo compound per mF. The diazotype film has good keeping qualities.

A sheet of the diazotype film, pressed between a reflectograiphic screen and a non-transparent original, for example a. page from a book, is exposed to the light of a high-pressure mercury-vapour lamp, with the screen turned towards the light-source and in contact with the sensitized surface of the film.

After the termination of the exposure the latent reflex copy is developed by applying on its image surface a layer of approximately 9 g./m. of the following developer:

g. of thiourea 10 g. of borax 17 g. of 3-methoxy sodium phenolate 4 g. of isopropyl naphthalene sulphonic acid as sodium salt a 2 g. of ethylene diamine tetra-acetic acid sodium salt 35 g. of sodium carbonate in 1000 cm. of Water.

The developed copy shows a strong brown image, the lines of which do not shown bleeding. The brown azodyestuff has good absorption for ultra-violet light. The copy therefore is very suitable as daughter original for the production of further copies on diazotype paper.

If instead of the above-mentioned diazo compound an equimolar quantity of the corresponding compound without a chloro substituent is used, the diazotype film manufactured with it develops more slowly and less completely. The azo-dyestutf of the copies on such a film has less absorption for ultra-violet light and the copies are less suitable as daughter originals than the copies according to this example. The azo-dyestufi image of the copies according to this example is more resistant to the action of acid than that of the copies on diazotype film manufactured with a corresponding compound without a chloro substituent.

The diazo compound used according to this example is prepared as follows:

Z-methoxy S-chloroaniline is converted with n-propyl bromide into Z-methoxy S-chloro N.N-din.propyl aniline (boiling point l152 C.) Upon nitration, 2- rnethoxy 4-nitro S-chloro N,N-di-n.propyl aniline (yellow needles, melting point 82 C). is formed, which is converted into the desired diazo compound by reduction and diazotization.

Example V White base-paper of weight 80 g./m. for the diazotype process, with an acid content such that it has a pH of 4.1 when moistened with water, is sensitized with a solution (at 18 C.) of:

21 g. of 4-di-n.propylamino 3-methoxy 6-chlorobenzene diazonium chloride, zinc chloride double salt 40 g. of tartaric acid 10 g. of boric acid g. of naphthalene 1.3.6-trisulphonic acid sodium salt 20 g. of 2-naphthol 3.6-disulphonic acid sodium salt 0.8 g. of methylcellulose in 1000 cm. of water and dried.

The sensitized surface contains approximately 0.55 millimole of the diazo compound per m. The diazotype paper has good keeping qualities. A sheet of the diazotype paper is exposed as in Example I.

The latent diazotype copy thus obtained is developed by exposing it for some tens of seconds to hot concentrated moist ammonia vapour. A strong violet positive image is obtained, the colour of which does not change 7 when the copies are kept in a moist atmosphere.

If instead of the above-mentioned diazo compound an equimolar quantity of the corresponding compound Without a chloro substituent is used, again a copy with a violet image is obtained, the colour of which, however, changes considerably when the copy is kept in a moist atmosphere.

Example Vl White base-paper of weight 80 g./m. for the diazotype process is sensitized with a solution (at 18 C.) of:

21 g. of 4-N-methyl N-benzylamino 3-methoxy 6-fluorobenzene diazonium chloride, zinc chloride double salt 5 g. of tartaric acid 2 g. of boric acid 20 g. of naphthalene 1.3.6-trisulphonic acid sodium salt 0111. of polyvinyl acetate dispersion (Vinnapas H60) in 1000 cm. of water and dried.

The sensitized surface contains approximately 0.5 millimole of the diazo compound per m9. The diazotype paper has good keeping qualities.

A sheet of the diazotype paper is exposed and developed as in Example I. The developed copy shows a strong dark-brown positive image on a clear White background. The lines of the image do not shown bleeding. Upon moistening with an acid liquid with pH 2, the amdyestutf does not show a change of colour. 7

If instead of the above-mentioned diazo compound an equimolar quantityof the corresponding compound without a fluoro substituent is used, a precipitate is formed in the sensitizing liquid.

If the non-fluorinated diazo compound is used in the absence of naphthalene 1.3.6-trisulphonic acid, no precipitate is formed, but the keeping qualities of the diazotype material manufactured with this sensitizing liquid 'are considerably inferior to those of the material according to this example.

The azo-dyestufr" image of the copies on diazotype material manufactured with the corresponding compound without a fiuoro substituent upon moistening with the above-mentioned acid liquid shows a change of colour.

The diazo compound used according to this example is prepared as follows:

O-nit-ro p-tluoro-anisole is reduced. The 2-methoxy 5- fiuoroanihne thus obtained is tosylated. The product formed, Z-methoxy 5-fiuoro N-tosyl aniline (melting point -l26 C.), is methylated to 2 methoxy 5 fluoro N-methyl N-tosyl anilide (melting point 125 C.), and subsequently hydrolyzed to 2-methoxy S-iluoro N-methyl aniline. This product is benzylated to Z-methoxy S-fluoro N-methyl N-benzyl aniline (boiling point -190 C.) and subsequently nitrated to 2-methoxy 4-nitro S-fiuoro N -methyl N-benzyl aniline (melting point 60-61 C.). This compound is reduced and worked up into the diazo compound in the usual way.

Example VII Natural transparent paper of weight 70 g./ 111. for the diazotype process is sensitized with a solution (at 18 C.) of:

22 g. of 4-dimethylarnino 3-benzyloxy' 6-chloro benzene diazonium chloride, zinc chloride double salt 10 g. of citric acid 15 g. of naphthalene 1.3.6-tri-sulphonic acid sodium salt 20 cm. of polyvinyl acetate dispersion (Vinnapas H.60)

in 1000 cm. of Water and dried.

The sensitized surface contains approximately 0.5 millimole of the diazo compound per mfi. The diazotype paper has good keeping qualities.

A sheet of the diazotype paper is exposed as in Example I. The latent diazotype copy thus obtained is developed by applying on its image surface a layer of approximately I 8 g./m. of the following developer:

in 1000 cm. of water.

The developed copy shows a strong dark-brown positive image, the lines of which do not show bleeding. It is suitable as a daughter original for the production of further copies on diazotype paper.

If instead of the above-mentioned diazo compound an equimolar quantity of the corresponding compound without a chloro substituent is used, a precipitate is formed in the sensitizing liquid. If the non-chlorinated diazo compound is used in the absence of naphthalene 1.3.6- trisulphonic acid, no precipitate is formed, but the keeping qualities of the diazotype material manufactured with this sensitizing liqud are considerably inferior to those of the material according to this example.

The diazo compound used according to this example is prepared as follows:

Z-nitro 4-chlorophenol is converted with benzyl chloride into 2-nitro 4-chlorophenylbenzyl ether (melting point 85-86 C., yellow crystals). This compound is reduced to Z-benzyloxy S-chloroaniline (melting point 60 C.) and subsequently methylated to Z-benzyloxy S-chloro N,N-dimethyl aniline (melting point 40 C.). Upon nitration, 2-benzyloxy 4-nit-ro 5-chloro N,N-dimethyl aniline (red leaflets, melting point 107 C.) is formed. This compound is reduced and worked up into the di-azo compound in the usual way.

I claim:

1. Diazotype material comprising a sheet material carrying a light-sensitive layer containing a diazo compound of the general formula in which X is an anion, Y is an atom selected from the class consisting of fluorine and chlorine atoms, and R R and R are groups selected from the class consisting of alkyl groups having at most 4 carbon atoms and aralkyl groups having at most 11 carbon atoms, and R R and R contain together at least 6 and at most 17 carbon atoms.

2. One-component diazotype material according to claim 1, wherein, in the said diazo compound R R and R contain together at least 8 and at most 17 carbon atoms and wherein the said layer contains no azo coupling component.

3. One-component diazotype material according to claim 2, wherein, in the said diazo compound R represents a benzyl group.

4. A diazotype material comprising a sheet-like support carrying a light-sensitive composition containing a diazo nium salt of 4-N methyl N benzylamino 3 methoxy 6chlorobenzene.

5. A diazotype material comprising a sheet-like support carrying a light-sensitive composition containing a diazonium salt of 4-N-methyl N benzylamino 3 methoxy 6-ch1orobenzene.

6. A diazotype material comprising a sheet-like support carrying a light sensitive composition containing a diazonium salt of 4-di-n.propyl-amino S-methoxy 6-chlorobenzene.

7. A di-azotype material comprising a sheet-like support carrying a light-sensitive compositioncontaining a diazoniurn salt of 4-N-methyl N benzylamino 3 methoxy 6-fiuorobenzene.

8. A diazotype material comprising a sheet-like support carrying a light-sensitive composition containing a diazonium salt of 4-dimethyl-amino S-benzyloxy 6-chlorobenzene.

9. One-component diazotype material comprising a sheet material carrying a light sensitive layer containing as a stabilizer a compound selected from the class consisting of napthalene 1.3.6-trisulfonic acid and salts thereof, together with a diazo compound of the formula in which X is an anion, Y is an atom selected from the class consisting of fluorine and chlorine atoms, and R R and R are groups selected from the class consisting of alkyl groups having at most 4 carbon atoms and aralkyl groups having at most 11 carbon atoms, and R R and R contain together at least 6 and at most 17 carbon atoms.

References Cited by the Examiner UNITED STATES PATENTS 2,037,542 4/36 Schmidt et a1. 9691 2,113,944 4/38 Leuch.

2,405,523 8/46 Sease et al. 9675 2,537,097 1/51 Sliikin 9675 2,551,133 5/51 Jennings et a1 96-75 2,593,911 4/52 Neumann 9691 2,657,141 10/53 Kessels 96-49 2,792,303 5/ 57 Sanders et al 96-49 2,822,272 2/ 58 Kosalek et al. 2,937,085 5/60 Seven et a1 96---75 X FOREIGN PATENTS 643,309 9/ Great Britain.

OTHER REFERENCES Venlcataraman: Synthetic Dyes, vol. I, 1952, page 413. Saunders: The Aromatic Diazo Compounds (1949),

pages 359-361.

Organic Chemistry, College Outline Series, by Degering, Barnes & Noble, N.Y., 1951, page 250.

NORMAN G. TORCHIN, Primary Examiner.

CHARLES B. PARKER, MILTON STERMAN, PHILIP E. MANGAN, ABRAHAM H. WINKELSTEIN,

Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,169,869 February 16, 1965 Andreas Joseph Johannes Hendrickx It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 10, lines 5 and 6, strike out "4Nmethyl N-benzylamino 3-methoxy 6-chlorobenzene" read 4N-n.propyl N-benzylamino 3-methoxy 6chlorobenzene Signed and sealed this 27th day of July 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attcsting Officer Commissioner of Patents 

1. DIAZOTYPE MATERIAL COMPRISING A SHEET MATERIAL CARRYING A LIGHT-SENSITIVE LAYER CONTAINING A DIAZO COMPOUND OF THE GENERAL FORMULA 